What Marylanders need to know about the mu variant

As the delta variant continues to spread, creating a surge in COVID cases in the United States and across the world, a new variant known as “mu” has emerged, raising concerns about the continued mutations of COVID-19 and whether the end of the pandemic is anywhere in sight.

At the end of August, the World Health Organization classified the mu variant as a “variant of interest,” noting that it would monitor the spread of the mutation after some lab tests indicated it may be more resistant to antibodies than previous strains of the virus.


Here’s what you need to know about the emerging variant:

Where did it come from and where has it spread?

The mu variant, named (like previous variants) after a letter of the Greek alphabet, was first identified in Colombia in January.


Since then, the mu variant has spread to more than 40 countries, including the United States, where around 2,500 cases have been reported, according to GISAID, a data-sharing hub.

It’s important to note that these cases only make up 0.1% of COVID cases in the United States, according to the U.S. Centers for Disease Control and Prevention.

How many cases of the mu variant are there in Maryland?

As of Tuesday, there had been 53 confirmed cases of the mu variant in Maryland, according to Charles Gischlar, a spokesman for the Maryland Department of Health.

These cases make up a small portion of the cases in Maryland, around 0.03% of cases that have been analyzed to determine which variant they came from, according to a tweet Wednesday from Michael Ricci, communications director for Gov. Larry Hogan.

This is lower than the overall rate of mu in the U.S. Delta remains the dominant threat in Maryland, making up more than 99% of all new cases tested for their origin over the past four weeks, Ricci wrote.

The alpha variant makes up 0.55% of recent cases in Maryland and the gamma variant was found in 0.26% of tested samples, he tweeted.

Should I be concerned about the mu variant?

While some lab tests indicated that the mu variant is capable of evading antibodies, developed from previous infections and vaccinations, Dr. Gigi Gronvall, a senior scholar at the Johns Hopkins Center for Health Security and trained immunologist, said this has yet to be confirmed outside a lab setting.

A report from England’s public health agency in August suggested the variant could be vaccine-resistant, but said more real-world data was needed.


Dr. Anthony Fauci, the top U.S. infectious disease expert, said in August that the United States was “keeping a very close eye” on the mu variant but did not see it as an immediate threat.

Mu also makes up a tiny portion of current COVID-19 cases in Maryland and the United States. There is little real-world data on its behavior.

“As of right now, it’s not in the race,” Gronvall said.

For now, the delta variant remains the prominent threat.

“What is less concerning about mu is that it doesn’t seem to be taking off. It doesn’t seem to be making as many copies of itself as quickly as delta does,” Gronvall said.

So far, none of the emerging variants, including mu, seem to be increasing the severity of the disease, according to Gronvall.


Although the thought of a new variant is jarring, Gronvall said mutations and the emergence of new virus variants are typical and will continue to happen as long as people remain unvaccinated and allow COVID to spread.

Dr. Boris Lushniak, dean of the School of Public Health at the University of Maryland, said the primary concern of the pandemic is not one individual variant, but the evolution over time of the COVID virus.

Lushniak noted that there have been many variants, including iota, that have emerged during the pandemic but quickly disappeared from public conversation, only to be replaced by another variant.

“We are probably going to learn a lot of the Greek alphabet in order,” Gronvall said.

Gronvall said talk of variants should not distract people from focusing on taking precautions to avoid illness and help end the spread of COVID-19.

“From an individual standpoint, your goal should be just to not get COVID,” Gronvall said.


“The big picture is we have to stop replication, we have to stop people getting sick with this and there’s only one path out of it, to continue public health measures ... and vaccinate,” Gronvall said.

The Associated Press contributed to this article.